A digital modulation apparatus capable of generating a modulated code so that binary slice is correctly performed when reproducing is provided. To achieve this, in a digital modulation apparatus (10A), a DSV change amount calculator (15) calculates change amounts (.DELTA.DSVa, .DELTA.DSVb) in DSVs of candidate modulated codes (CODEa, CODEb) generated by a modulated code generator (11). A modulated code determinator (13) compares the change amounts (.DELTA.DSVa, .DELTA.DSVb), and determines that the candidate modulated code having a smaller absolute value should be selected as a modulated code (CODE). A modulated code selector (14) selects one of the candidate modulated codes (CODEa, CODEb) which is determined by the modulated code determinator (13), and outputs the selected code as a modulated code (CODE) for source data (DATA).